Machines are known, at least partly automated or manual, used for washing containers for liquids, for example, but not only, for bottles, feeding bottles, drinking troughs or others, used for feeding, by means of spouts made on the closing lids, of animals such as for example laboratory guinea pigs or rodents or others. The containers and the corresponding spouts can be of different sizes and volumes, in order to adapt to the different sizes and needs of the animals to be fed. In particular, the diameter of the spouts normally available on the market varies inside a range between a minimum value, suitable for small animals, and a maximum value, for bigger animals.
Such washing machines are generally structured with several operating stations disposed in succession with respect to each other, including a loading station for the closed containers, a removal station to remove the lids from the containers, or de-lidding station, a washing station, a filling station and a closing station, of the washed and re-filled containers, in which the lids, washed in their turn, are repositioned on the containers.
The lids are normally constrained by a water-tight seal to the containers, therefore, in known solutions which provide the removal station, the closed containers are opened by removing the lids using suitable opening devices.
These known devices are provided with mechanical holding members of the lids, once they have been removed from the containers, driven mechanically and with the function of generating a friction force on the spouts of the lids, both to prevent these falling due to gravity after opening, and also to allow handling during working.
Known mechanical holding members however are limited because they are not effectively adaptable to the different sizes of the spouts and are therefore not very versatile and not completely reliable above all in holding spouts with smaller diameters. This is even more disadvantageous with an increased variability of the diameters of the spouts treated in a single washing machine.
An example of an opening device is described in the international patent application WO-A-2001/045256 in the name of the present Applicant, in which a pneumatic action is exploited, induced to separate the lid from the container and in which such devices are provided with mechanical holding devices of the pliers type, which actuate a radial gripping action on the lid in order to hold it in the steps of extracting or separating and transporting the lid.
However, even if they are effective in guaranteeing a correct holding of the lid during said steps, these mechanical holding members need specific actuator mechanisms, both to define the holding and also the release of the lid.
Actuating these actuator mechanisms either to grip or release requires specific commands and controls, with corresponding times and costs of programming and coordination with the other units and working stations.
As well as having their own programming and manufacturing costs, these commands can have malfunctions that can cause slowing down or operating interruptions, and also require periodic maintenance and control interventions.
A device is also known and described in the international patent WO-A-2001/158085 in the name of the present Applicant, for opening containers and for holding corresponding lids which uses an elastic member, deformable by means of mechanical elements, such as pins or pegs, in order to keep clamping and holding elements radially thrust against the spout of the lid.
This known device also comprises one or more extractor elements which, located inside the air passage pipes of the corresponding removal members, exert an axial thrusting action on the spout of the lid, overcoming the elastic action exerted by the holding means, so as to bring it outside the air passage pipe.
Even though this device allows to limit the times for opening the containers and to carry out this operation simply, it is not completely reliable because of the possible variability of the diameters of the spouts, in particular for spouts with smaller diameters, in cases where there is a wide variability of the diameters of the spouts. Indeed, since the holding members are the mechanical type and are generally calibrated on larger diameters, they are not normally suitable to effect a grip or apply a force that is reliable and sufficient to hold the spouts of smaller diameters.
A further disadvantage derives from the fact that the thrust force exerted by the extractor elements on the spouts, if not suitably controlled, can cause the latter to be deformed or damaged and can render them useless.
A device to hold lids of containers is also known from the international patent application WO-A-2011/138661 in the name of the present Applicant. This known device comprises a holding member provided with a mechanical clamping member selectively activated to grip the spout of a corresponding lid.
Furthermore, application DE-A-3401386 describes a closing head to screw a screw top to a threaded opening of a bottle. The device described in DE-A-3401386 is not suitable to open and also hold the lids removed from the container, in particular it is not suitable for containers with lid with a spout as discussed here. This known device comprises a single circuit for a fluid under pressure by means of which to deform an elastic diaphragm member fitted on the screw top. In this way, the diaphragm elastic member grips on the top, and the closing head, by means of rotation, can screw the screw top.
It is therefore a purpose of the present invention to obtain a device for opening containers and holding the corresponding lids that is effective and reliable in the holding of the lids, irrespective of the variability of diameters of the spouts of the lids to be treated.
It is also a purpose of the present invention to obtain a device that allows to open the containers simply, economically and efficiently, that allows to reduce the overall execution times to a minimum, without damaging the spouts of the lids.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.